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991.
甘南玛曲沼泽湿地土壤微生物量、理化因子与土壤酶活的关系 总被引:6,自引:1,他引:5
对甘南玛曲沼泽湿地6个样地的微生物量与土壤酶活性及其土壤理化性质之间的关系进行了研究.结果表明:纤维素酶活性在冬季达到高峰,其余5种土壤酶活性分别在春季和秋季达到高峰;硝化细菌数量与过氧化氢酶、纤维素酶、脲酶、碱性磷酸酶有较显著的负相关关系;微生物量与酶活性之间存在极显著相关关系,其中微生物量因子中的放线菌、氨化细菌、硝化细菌和土壤酶活性因子中的酸性磷酸酶、碱性磷酸酶、中性磷酸酶是引起相关性的主要因素;酸性磷酸酶活性与土壤含水率、pH值、硝态氮含量、氨态氮含量都有密切的关系,过氧化氢酶活性可以通过有机质的含量来反映,脲酶活性可以通过土壤的含水率来反映,碱性磷酸酶活性可以通过电导率来反映. 相似文献
992.
白云岩是一种常见的碳酸盐岩,它广泛分布在古代碳酸盐岩台地中,却很少见于全新世沉积物中,这构成了一个未解之谜。近20多年的研究成果表明,早期成岩过程中微生物参与的硫酸盐还原反应、甲烷生成和厌氧氧化反应以及有氧呼吸作用能够促进白云石的沉淀:细菌细胞和胞外聚合物(EPS)带有负电荷,能够聚集溶液中Mg2+和Ca2+;同时上述氧化还原反应产生HCO3-,提高了孔隙水中反应物的浓度;这样在细菌细胞周围形成一个对白云石超饱和的微环境,有利于白云石的沉淀。这是一种新的白云石成因模式,微生物活动和有机质是影响白云石形成最重要的因素,特殊的球状形态和碳同位素特征是鉴别有机成因白云石的重要标志。白云岩有机成因模式为认识地质历史时期大套白云岩的成因、探索"白云岩之谜"提供了新的思路。 相似文献
993.
GUQianqun LUJia CUIChengbin ZHUTianjiao FANGYuchun LIUHongbing ZHUWeiming 《中国海洋大学学报(英文版)》2004,3(2):150-156
1 Introduction Sincetheearly 196 0s ,oceanhasbeenconsideredasanewanduntouchedsourceofpotentiallyusefulcom pounds .Theresultsfromtheresearchesontheorgan ismssuchassponges,softcorals ,algae ,ascidians ,bryozoansandmollusks ,havedemonstratedthatma rineorga… 相似文献
994.
十红滩铀矿床中微生物及其成矿作用实验研究 总被引:4,自引:1,他引:4
利用生物学方法对新疆十红滩铀矿床各亚带中的微生物进行了分离和鉴定,利用矿床中赋存的硫酸盐还原菌对矿床地下水中的铀进行了还原实验,并设计了水—岩—菌三相实验系统对铀矿床中的微生物成矿作用进行了模拟实验。结果表明:十红滩铀矿不同亚带岩石中主要微生物类群的分布特征不同,呈现出明显的生物地球化学分带性。其中优势菌硫酸盐还原菌能够通过代谢作用将矿床地下水中的铀还原沉淀。硫酸盐还原菌也可利用岩石中的有机碳作为营养物质进行生长繁殖,并将铀还原沉淀。 相似文献
995.
996.
贵州猫场铝土矿是中国西南重要的铝土矿床之一。在对该矿床的研究中,笔者在铝土矿层和黄铁矿层之间的过渡层中发现了微米级铁质微球粒。能谱和X射线衍射分析表明,该种微球粒几乎完全由铁的氧化物和氢氧化物组成,铝和硅的含量较少,经研究认为其矿物组成主要应为针铁矿。在含铁质微球粒的层位中,经常会出现一些具有溶蚀特征的黄铁矿小晶粒,甚至还有铁质微球粒包裹残余黄铁矿的现象出现。这些现象表明了微球粒的形成和黄铁矿的溶解、氧化具有极大的相关性。而在黄铁矿的溶解和微球粒的形成过程中,微生物通常都扮演着极其重要的角色,对铁质微球… 相似文献
997.
Hua JIANG Huxiao JING Weixiao QING 《中国地球化学学报》2006,25(B08):3-3
It is estimated that the poisonous heavy metals released to the environment come up to million tons. Such great amounts of poisonous heavy metals result in a serious bane to ecosystem and human health. The valid control of spreading and pollution of heavy metals in the environment has hence become an urgent issue of the moment. In this study, through tameness and induction of living creature's tolerance from dirty mud, using microbial technology we have cultivated some anti-heavy-metal microbes able to resist the pollutions from poisonous chemical elements such as arsenic, chromium, cadmium, hydrargyrum, and plumbnm, four of which are fungi and five are bacteria. Atomic absorption spectroscopy and atomic fluorescence spectrophotometry analyses showed that, to the same chemical element, fungi have stronger resistance than bacteria by one time or so. 相似文献
998.
Franco Tassi Orlando Vaselli Erik Fernandez Eliecer Duarte Giordano Montegrossi Angelo Minissale 《中国地球化学学报》2006,25(B08):228-229
Laguna Caliente is a crater lake hosted within the Poas volcano (Costa Rica) that is considered one of the most active volcanic systems of Central America. Laguna Caliente is characterized by extremely low pH (-1) and very high TDS values (up to 33700 mg/L), although, in the last two decades, the lake volume has significantly changed, mainly in relation to variations of the fumarolic activity. In this work, we present the chemical and isotopic compositions of water and dissolved gases collected along the vertical profile of the lake in order to constrain the main processes that control its physical-chemical features. Water and gas samples were collected. Laguna Caliente has a Ca (Mg)-Cl (SO4) composition, typical of acid-brine lakes of active volcanic systems. Among dissolved gases, CO2 content, by considering the low pH, is particularly high (up to 18.1% by vol.), and relevant amounts of oxygen (15.8. % by vol.), preventing the formation of any anoxic hypolimnion, are also present at the maximum depth. Temperature and chemical species remain almost constant along the vertical profile, with the exception of F- that shows a moderate increase with depth and CI and SO4^2-, whose contents increase by more than 10% at the depth of 20 m, and, below 20 m, decrease to values similar to those measured at surface. This compositional stratification may be tentatively explained by the complex combination of, at least, three processes: (1) input of high-temperature volatiles from sub-lacustrine fumaroles, (2) loss of HCl and H2S from lake surface through evaporation, and (3) SO4^2- and CI consumption due to microbial activity at the bottom of the lake. 相似文献
999.
Mengchang HE Yan SUN 《中国地球化学学报》2006,25(B08):264-264
Sorption of hydrophobic organic chemicals by various components influences their behavior and fate in environment. In the natural environment, mineral components, organic matter and microorganism didn't exist alone. They combined or reacted one another and formed the mineral-humic, mineral-microorganic and mineral- humic- microorganic complexes. A clear understanding of the sorption of organic chemicals by the complexes of mineral and humic acid and/or microorganism will help to determine their sorptive mechanisms in environment. In this paper, the sorption patterns of phenanthrene on the complexes of kaolinite and different organic component (humic acid and microorganism) have been carried on. The results show that the combination of HA and kaolinite not only changed the structure of HA, but also modified the surface chemistry of clay mineral. Interaction between HA and kaolinite is presumably ascribable to coulombic interactions and ligand exchange between the -COOH groups of HA and OH groups at the kaolinite surface. During the sorption on mineral surface, aliphatic fractions of HA were preferentially sored by kaolinite while aromatic fractions were left in the solution. More linear isotherms and higher Koc values were observed for kaolinite-HA complex in comparison of the pure HA. The sorption capacity of kaolinite-HA complex increased with increasing ionic strength and pH, and showed more nonlinear character. Kaolinite, microorganism and kaolinite-microorganism complex can all sorb phenanthrene, but the sorption capacity significantly differed. Bacterial cell sorbed more phenanthrene than kaolinite. The biofllm coating of kaolinite affected its sorption to phenanthrene. Kaolinite with biolfilm coating sorbed more phenanthrene than that without biofilm coating. The sorption capacity of kaolinite-microorganism complex decreased with increasing ionic strength and decreasing pH, but showed more nonlinear character. Both HA and microorganism can alter the nature of kaolinite sorbing phenanthrene respectively. 相似文献
1000.
湖北清江和尚洞石笋脂肪酸的古气候意义 总被引:15,自引:0,他引:15
利用气相色谱-质谱联用仪从湖北清江和尚洞石笋中检测出一些正构脂肪酸, 碳数分布范围主要为C14~C26, 主峰碳为C16, 次主峰为C22, 与上覆土壤中以高碳数分子为主的正构脂肪酸分布形式略有不同. 石笋中的脂肪酸除了土壤生态系统提供部分来源外, 洞穴滴水和洞穴内部的微生物也可能贡献了一部分低碳数分子. 不饱和与饱和脂肪酸的比值和氧同位素具有一定的对应关系, 而且高值对应于寒冷气候事件(北大西洋冰筏漂砾事件H1). 这与温度对微生物活动及其生理反应的影响有关. 脂肪酸指标记录的气候事件与前期报道的来源于土壤生态系统中的脂肪醇和脂肪酮记录的气候事件有一定差异, 可能是不同类脂物分子的地球化学行为差异和生态系统生物组成差异的体现. 相似文献